Overview
Climate change refers to long-term changes in temperature, weather patterns, and related environmental conditions. These changes can affect human health directly, such as through extreme heat, and indirectly, such as through poorer air quality, unsafe water, food insecurity, and changing disease patterns. Health effects may be short-term, like dehydration during a heat wave, or long-term, like worsening heart or lung disease.
Key Symptoms
Climate-related health problems do not cause one single set of symptoms. People may develop signs of heat illness such as heavy sweating, dizziness, weakness, headache, nausea, confusion, or fainting. Smoke or air pollution may lead to coughing, wheezing, chest tightness, or trouble breathing. Stress after disasters may cause trouble sleeping, anxiety, low mood, or difficulty concentrating.
Causes and Risk Factors
Health risks can rise with extreme heat, wildfire smoke, air pollution, flooding, storms, drought, and shifting patterns of allergens and infectious diseases. Risk may also increase when homes, workplaces, or neighborhoods have limited cooling, poor ventilation, unsafe water, or weak disaster protection. People who already have heart disease, lung disease, kidney disease, diabetes, or mental health conditions may be affected more strongly.
Who Is Affected
Climate change can affect anyone, but some groups are more exposed or more vulnerable. Higher-risk groups often include older adults, infants and children, pregnant people, people with disabilities, people with chronic illness, and those who work outdoors. Communities with lower incomes, unstable housing, limited healthcare access, or frequent exposure to pollution and disasters may carry a heavier burden.
Prevention
Practical steps depend on the local climate risks. During hot weather, stay hydrated, reduce strenuous activity in peak heat, use cool indoor spaces when possible, and check on people who may need help. Follow local alerts about heat, storms, wildfire smoke, and air quality, and make a household plan for emergencies, medicines, water, and important documents. Community actions such as cleaner energy, greener urban spaces, and stronger public health systems also help protect health.
Living With It
Living with climate-related health risks often means planning ahead and adapting daily routines. People with asthma, heart disease, or other chronic conditions may need to pay close attention to air quality, heat, and emergency disruptions. It can also help to know where to go for cooling, clean air, safe water, shelter, and trusted local health information.
Diet and Lifestyle
Healthy daily habits can support resilience during climate-related stress. Drinking enough fluids in hot weather, eating regular meals, and avoiding overexertion during extreme heat can lower the chance of heat illness. If smoke or pollution levels are high, reducing outdoor activity may help lessen breathing problems. Sleep, social support, and stress-management practices may also support mental well-being during and after extreme events.
When to Seek Medical Care
Seek medical care if heat, smoke, storms, or other climate-related exposures lead to symptoms that are new, worsening, or hard to manage. Examples include ongoing vomiting, signs of dehydration, worsening asthma symptoms, chest discomfort, severe anxiety, or problems after floodwater exposure. People with chronic illnesses should contact a healthcare professional if extreme weather or evacuation disrupts medicines, oxygen, dialysis, or other essential care.
When It May Be an Emergency
Emergency care may be needed for signs of heat stroke, severe breathing trouble, bluish lips, chest pain, confusion, seizures, fainting, major injuries, or symptoms of severe allergic reaction. Urgent help may also be needed during disasters when someone is trapped, unable to get essential medicines, or exposed to dangerous floodwater, smoke, or extreme temperatures. Follow local emergency guidance and call emergency services right away if there are life-threatening symptoms.